Shock-resisting concrete



I06. COMPOSITIONS,

COATING OR PLASTIC.

Dec. 10, 1935.

Examine! w. w. WILLIAMSON SHOCK RESISTING CONCRETE Filed Dec. 22, 1933INVENTOR.

ATTORNEYS.

8 Patented Dec. 10, 1935 COATING R PLASTIC.

UNITED STATES PATENT OFFICE SHOCK-RESISTING CONCRETE Wilbur WorthWilliamson, Oakland, Calif., as-

signor to The Pacific Lumber Company, San Francisco, Calif., acorporation of Maine Application December 22, 1933, Serial No. 703,633

2 Claims. (Cl. 106-24) This invention relates to cement construction,about A to 10 pounds, the more serviceable range particularly walls androofs of buildings, and it being from about to 5 pounds. This fiber ishas for its principal object ashock-resisting resilunground, as longresilient fibers are required, ient bodied cement or concrete slab,block, or wall and it may be introduced either before, during 5construction, which will not shatter or crack or after filling the masswith the gaseous bubbles, 5 under concentrated violent impact as ofmissiles, though it is more practical to remove the cement falling rocksfrom great heights above, projectiles mass from the gas or air-chargingapparatus of shot with destructive intent, etc. Other advanwhatever kindused, and incorporate the fine fiber tages of the compound cement bodyinclude in any simple mixer of the type having revolving l0 structuraluse, sound and thgmaLinsulation, and arms as used for mixing dough,asphalt, plaster,

light-weight tough fireproof partition construcor other viscousmaterials. tion. The fiber may be introduced mist or The accompanyingdrawing shows in greatly though the latter form is referable as itcarries a great manymore a1r bells 1n"to the mass. Mixenlarged elevationthe characteristic appearance of an average sample of my improved cementor ing should be made in as short a time as will still 15 show the fiberto be well covered with cement,

concrete product though it is impossible to perbut no longer asprolonged mixing seems to tend fectly show the mass of tangled fiberstherein.

The basis of the invention is an aerated or toward escape of bubblesfrom the mass. When as-filled cementitious mixture of m suflicientlymixed, which should be in a minute nature of the air or gas mixed porouscement or two, the mass may be poured or pushed into 20 mass known inthe art as Bubblestone or cellular forms for walls, slabs, blocks, orany other shape, concrete, which is filled with a myriad of small ortroweled in place or spread in one or several air or gas bubbles, and towhich mass is incorpoheavy layers as from a half inch to ten inches orrated by stirring, a quantity of finely shredded more, depending on theshock-absorbing or blowresilient fibrous matter such as redwood barkresisting qualities desired. 25 s ded to a condition about as fine asher or The incorporation of the extremely fine, wool, and thenpermitting the mass to set. shredded wool-like redwood bark fiberfunctions uch cellular cement or concrete masses are to hold the myriadsof bubbles in place during made by various processes, such as by forcingthe setting of the mass, and makes it possible or beating air or gasbubbles into a liquid mixto use much less, or altogether avoid the use30 ture of Portland cement and water or with sand of the frothingmixture in some cases, and when or other fine aggregate,though'preferably by the the block or slab is set it has greatlyincreased additional incorporation of a bubble sustaining tensilestrength over other light weight concretes or fr ine mp mp f a l in andif subjected to a violent blow as of a hammer material such as caseinand water together with will crush locally only until the containedfibers 35 calcium hydrate, all as set forth in the Bubbleform a mattedresilient mass to stop further stone Companys Patents Nos. 1,717,319 ofJune 11, progress of the hammer, but it will not fracture. 1929, and1,769,275 of July 9 o which re In fact its power to absorb sudden blowsmakes erence is mad as s merely forms One Of the it ideal as aprotective shield over the roofs of 40 desirable cellular cement orconcrete bases prefpower houses adjacent rocky mountains or banks 40erably used by applicant, t g other cemeflts from which large rocks maybecome loosened and such as magneslte cement mfewlse begten up wlthprecipitated, also as a protection to arsenals and air or blown full ofgas or air bells W111 also serve other buildings against deliberateattack as a base for my improvements though it will not Besides finelyShredded redwood bark I have so effectually resist outside exposure tothe eletried other finely shredded barks, also various liquid bubbleimpregnated cement mass finely shredded woods cane fiber etc., and whilem they all Have value m' carryin'g out the invention, I may be ofvarious densities, richness of ac en the shredded redwood bark of afineness about and admixture of inert matter such as sand, (11- in tatomaceous earth, etc., depending on the use and equal to hair wool isPreferred as it 15 en 50 even after having been embedded in the cementstrength demanded of the final product, so that its weight per cubicfoot may run from about 20 for a long time, and is quite proof againstdeterioration through the action of air or moisto 80 pounds per cubicfoot, and to a cubic foot of which mixture the finely shredded redwoodture creeping into the hardened cellular prodbark may be added inquantity running from uct. Another valuable feature is that a surface 55o. a o.- 1

badly injured as by a tremendous blow, may be easily repaired by blowingout the loose particles, wetting and patching in with new material tointerlock with the adjacent fibers with substantially original strengthwhen set. Still another advantage of the material over the ordinarycellular concretes and Bubblestone is the fact that it will not run outof small cracks and holes so hard to avoid in form work, but speedilyplugs up any which may exist in the forms.

My product is not to be confused with mere fibered plaster, for itcontains a very large proportion of fiber adapted to form ashock-absorbing mat when the concrete is subjected to impact, and thefiber is of such a nature to cooperate with the bubbles artificiallyformed or introduced into the mass as to stabilize them during settingas well as to cooperate with them in gradually absorbing any blowapplied.

In the drawing l represents the side of a cement or concrete block orhardened mass made in accordance with my invention and in which 2 arethe bubbles of various sizes, 3 the sand or other inert matter (whenused) and l the finely shredded redwood bark.

In my appended claims my use of the words cellular concrete or cementmixture is intended to include any of the light weight cellular cementmixtures however produced.

Having thus described my invention and some of its properties and uses,what I claim is:

1. A shock-resisting concrete having a cellular body and throughout thebody an intertwined mass of long shredded redwood bark fibers inquantity running from about one-half to five pounds of fiber per cubicfoot of concrete whereby a substantially unbreakable mat is formed at apoint of severe impact.

2. A shock-resisting concrete having a highly cellular body filled withartificially produced gas cells and a quantity of long finely shreddedredwood bark fiber in amount from one-half to five pounds per cubic footof concrete, intertwined throughout its mass to form a resilientsubstantially unbreakable mat-like mass upon severe impact.

WILBUR WORTH WILLIAMSON.

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